Quickly opening the panel (on a WPCOM site) prevents keyboard shortcut binding

[jblz]

I did:

• Visited a WPCOM-simple site (*.wordpress.com on the front-end or wp-admin)
• Quickly expanded the Notifications panel (by pressing the n key, but clicking the bell triggers this as well)
• Tried to navigate the note items with the j & k keys so I could interact with them

I saw:

• "nothing happened" when I hit the keyboard -- no note was selected and I could not interact with them until I clicked into the notifications panel. After that, key commands worked as expected

I expected:

• Keyboard commands to work on the site any time the panel is displayed

Asides:

• I think this is some sort of race condition because If I let the page sit for a few seconds to "fully load" the key commands work as expected.
• This does not seem to affect my Jetpack site (with or without the "WordPress.com Toolbar" setting enabled)
• Tested in Chrome & Firefox on the Mac